Structural and antiferromagnetic properties of Sm-doped chrysene

The experimental discovery of superconductivity was reported in Sm-doped chrysene with Tc∼5 K, which provides vital material for exploring unique superconducting mechanism of rare-earth metal doped polycyclic aromatic hydrocarbons. Here the crystal, electronic structures and magnetic characteristics of Sm-doped chrysene have been investigated by the first-principles calculation using the generalized gradient approximation (GGA) plus U method, also including van der Waals correction. We find that Sm-doped chrysene with C2/c space group is the most stable where doped Sm atoms stay on the relative middle of chrysene molecules. This material is stabilized at antiferromagnetic ground-state with the metallic feature. The calculated spin magnetic moment of Sm atom indicates that there are two electrons transferring from Sm to chrysene molecule. Within the framework of GGA+U, the C-2p electronic states mainly contribute to the Fermi surface. Electronic correlation effects are significant to understand the superconductivity in Sm-doped chrysene.